Bacterial infection tied to heart surgery device

At 74, Bob Marks is grateful to be alive after collapsing at his Hempfield home last summer with an aortic dissection, a tear in the wall of the major artery carrying blood out of his heart.

Marks, a retired Lutheran pastor and registered nurse, said he's thankful for the flight team that got him to the hospital and the surgeons who saved his life at Allegheny General Hospital.

But he's begun to wonder whether the myriad complications that plagued his recovery — fatigue, night sweats, pneumonia, influenza and shingles — could be related to a rare form of bacteria called non-tuberculous mycobacterium, or NTM, found in heater-cooler devices used in open-heart surgery in about 60 percent of U.S. hospitals. The devices in question are known as Stockert 3T units....

...The case linking the rare infection to a specific device has been emerging for years in a medical detective saga spanning three continents.

Experts now believe NTM finds its way into operating suites when water in an internal tank in the device becomes contaminated. Although the water never comes into direct contact with patients, droplets can work their way into the internal workings of the device, be picked up by a fan, dispersed into the air and land on the patient undergoing surgery.

The trail that culminated in the latest warnings began with anecdotal reports of the rare infection out of Western Europe about a decade ago. In 2015, WellSpan York Hospital in Eastern Pennsylvania became the first U.S. hospital to identify such infections among patients who had undergone open-heart surgery there....

...Things reached critical mass this year with the release of a new study from the Special Pathogens Laboratory in Pittsburgh that found NTM in 33 of 89 units from 23 hospitals in 14 states; Washington, D.C.; and Canada sampled from July 2015 through March 2017. The lab, one of a handful in the United States that specializes in water-borne pathogens, also found four of the units colonized for Legionella, the bacteria associated with Legionnaire's Disease.

John Rhis, a microbiologist who is vice president of Laboratory Services at Special Pathogens Laboratory, made headlines in June when he released his findings at the national conference of the Association for Infection Control and Prevention.

“If the unit was responsible for contamination with (NTM), it makes sense that these other organisms were contaminating the sterile field as well,” Rhis said.

“I was shocked at the level of contamination we found. About 15 percent of the samples we tested were so heavily contaminated with bacterial or fungal overgrowth that they were uninterpretable. So, the actual number of positive tests might have been higher,” he said.

Rhis said the NTM infections are so rare that many hospitals would never have tested for it.

“That's why it took so long for this to be worked out. It's an unusual pathogen, and it's pretty amazing that the link was even made,” he said.